nginx: Ensure zulip-include files are distributed to the right systems.

There were a few recently introduced bugs, and this also cuts down on
our having to review diffs that don't actually affect the relevant
server when doing updates.

(imported from commit 43f3cff9a414bc1632f45a8222012846353e8501)

puppet/zulip/manifests/app_frontend.pp

@@ -66,13 +66,12 @@ class zulip::app_frontend {
   }
   safepackage { $web_packages: ensure => "installed" }
 
-  file { "/etc/nginx/zulip-include/":
+  file { "/etc/nginx/zulip-include/app":
     require => Package["nginx-full"],
-    recurse => true,
     owner  => "root",
     group  => "root",
     mode => 644,
-    source => "puppet:///modules/zulip/nginx/zulip-include/",
+    source => "puppet:///modules/zulip/nginx/zulip-include-frontend/app",
     notify => Service["nginx"],
   }
   file { "/etc/nginx/zulip-include/app.d/":

puppet/zulip/manifests/nginx.pp

@@ -4,6 +4,16 @@ class zulip::nginx {
                    ]
   package { $web_packages: ensure => "installed" }
 
+  file { "/etc/nginx/zulip-include/":
+    require => Package["nginx-full"],
+    recurse => true,
+    owner  => "root",
+    group  => "root",
+    mode => 644,
+    source => "puppet:///modules/zulip/nginx/zulip-include-common/",
+    notify => Service["nginx"],
+  }
+
   file { "/etc/nginx/nginx.conf":
     require => Package["nginx-full"],
     ensure => file,

puppet/zulip_internal/manifests/loadbalancer.pp

@@ -3,25 +3,6 @@ class zulip_internal::loadbalancer {
   include zulip::nginx
   include zulip::camo
 
-  file { "/etc/nginx/zulip-include/":
-    require => Package["nginx-full"],
-    recurse => true,
-    owner  => "root",
-    group  => "root",
-    mode => 644,
-    source => "puppet:///modules/zulip_internal/nginx/zulip-include/",
-    notify => Service["nginx"],
-  }
-
-  file { "/etc/nginx/zulip-include/location-sockjs":
-    require => Package["nginx-full"],
-    owner  => "root",
-    group  => "root",
-    mode => 644,
-    source => "puppet:///modules/zulip/nginx/zulip-include/location-sockjs",
-    notify => Service["nginx"],
-  }
-
   file { "/etc/nginx/sites-available/loadbalancer":
     require => Package["nginx-full"],
     ensure => file,